Compact electronic equipment normally is assembled mechanically and requires high density and automatic mounting of various electronic components on a printed circuit board. Consequently, surface mount type electrical connectors have become important components in such electronic equipment.
Conventionally, a surface mount electrical connector includes a dielectric housing which is mounted to the printed circuit board and includes a plurality of terminals projecting out of one side of the housing. The terminals are bent downwardly in such a manner that leg portions or contact feet of the terminals may be soldered to the circuit traces on the printed circuit board.
One of the problems with surface mount connectors of the character described is that uneven or nonuniform contact forces often are created between the contact sections or terminal feet and the circuit traces on the printed circuit board. This is caused primarily because the terminals are individual or discrete components and it is difficult to maintain the contact sections or feet of the terminals in a coplanar array. Attempts have been made to solve this particular problem by establishing a "spring back" in the terminal legs, after forming, to resiliently bias the legs against a surface, thereby aligning the contact sections of the legs in the same plane and consequently ensuring that the feet of the legs are coplanar. However, such provisions are costly because of the requirement of separate steps in the manufacture of the connector, and the connector is made unnecessarily bulky because of the additional surfaces against which the legs are aligned.
Another problem with surface mount connectors having conventional stamped and formed terminals is that it is very difficult from manufacturing and assembly standpoint to align terminal ends which contact conductive traces on a printed circuit board in a single row on small centers.
This invention is directed to solving the above problems by using flexible circuitry which not only provides coplanar contact pads for engaging the circuit traces on the printed circuit board and aligns terminal ends in a single row, but the connector assembly itself can be maintained quite compact.